For Ken Master's Stages:
You probably should modify Ken Master's stages or provide an alternate .def file.

All of his stages need less verticalfollow (try .3-.4) and need floortension (try 30-50).  Otherwise, when one player jumps, the other goes offscreen.

The zoffsets are all too low.

The animations look funny in most of the stages.

The author probably didn't even test Kame's House.  There's a very noticeable black bar at the bottom because the stage graphic isn't big enough.

Otherwise, the multiple layers with differing deltas look fine.

For Jedah's Stages:
Similar problem.  All of the stages need less verticalfollow (try .3-.4) and need floortension (try 30-50).

The multiple layers with differing deltas look fine.

I'm not sure what the source graphics look like for Destroyed City, but it looks like it has rather significant color loss in the yellow sky and smoke.

The brick building on the left also appears to have masking issues.  (pixels/lines from the background showing through).